There is known a pressure regulator comprising a housing accommodating a straight-flow non-sealed gate member which includes tubular and disk-like portions rigidly interconnected therebetween; an adjustment spring being arranged inside the housing separated from the flow-through portion by seals, whereas an adjusting nut is provided at the outer portion of the housing (cf., e.g., USSR Inventor's Certificate No. 192,575, IPC F 06 k, published Mar. 6, 1967).
This pressure regulator is sufficiently small-size and simple to construct, although it is disadvantageous because of making use of movable (slidable) sealing connections. Friction forces in connections of this type are always pronounced at the initial stages of operation to affect reliable operation and cause self-oscillations; whereas after an extended use such friction forces tend to reduce to result in a possible failure due to resilient resonant oscillations caused by fluctuations in the pressure of liquid. In addition the adjustment spring in the above pressure regulator is highly susceptible to corrosion due to contact with the fluid tending to leak through the sliding seals.
There is also known a liquid pressure regulator comprising a housing having inlet and outlet chambers, an adjustment arrangement in the form of a spring, a pressure-sensitive element disposed in the outlet chamber of the housing, and a means for controlling the flow of liquid fashioned as a hollow resilient body of spherical shape fabricated from an elastic material and arranged inside the housing. Adapted to cooperate with this means is a seat which forms a gate therewith. The seat has the form of a hollow cone having perforations at the tapered surface thereof, disposed at the inlet chamber of the housing and facing by its base the outlet chamber of the housing (cf., e.g., USSR Inventor's Certificate No. 359,640, IPC G 05 d 16/6, published Jan. 9, 1973).
A change in the outlet pressure upsets the equilibrium of forces at the pressure-sensitive element, whereby the prevailing force is transmitted to the means for controlling the flow of liquid to deform the resilient body and change the number of open perforations in the seat.
Inherent in the aforedescribed pressure regulator is a disadvantage of possible skewing of the means for controlling the flow of liquid, which results in less accurate performance and reduced reliability of the pressure regulator. Contaminants and solid particles present in the liquid tend to accumulate in the center of the tapered seat. This in turn affects performance characteristics of the pressure regulator after a certain service time to necessitate its periodical disassembly and cleaning. In addition, another disadvantage resides in that the pressure regulator is structurally complicated and difficult to manufacture.